Arapahoe, ColoradoArapahoe is an unincorporated community and census-designated place in Cheyenne County, Colorado, United States. The population was 102 at the 2020 census.HistoryArapahoe was established in 1870. The Arapahoe, Colorado, post office opened on May 5, 1906. The Arapahoe post office has the ZIP code 80802. The town name honors the Arapaho Native American people who lived in the area.GeographyAt the 2020 United States Census, the CDP has an area of, all land.DemographicsThe United States Census Bureau defined the for the